1. Field of the Invention
This invention relates to nuclear steam generators and more particularly to apparatus for remotely repairing the tubes and tubesheet in a nuclear steam generator.
In pressurized water nuclear reactors primary fluid or coolant is pumped through a reactor and a steam generator, radioactive contaminants in the primary fluid are deposited on the tubes and in the channel head of the steam generator so that repair crews are subjected to significant radioactivity when working within the channel head. Therefore, in order to reduce the exposure of personnel to radiation, it is desirable to provide an apparatus which can be remotely operated and effectively inspect and repair the tubes and tubesheets within the steam generator.
2. Description of the Prior Art
Patent application Ser. No. 775,676, filed Mar. 8, 1977, and patent application Ser. No. 873,292, filed Jan. 30, 1978 show similar apparatus to that described in this invention, however, the previous apparatus could not operate on every tube in the portion of the head that contains the apparatus. While such apparatus was acceptable for normal repair work within the head when the apparatus is to be used in a retubing operation, it is necessary that the apparatus be able to perform operations on each and every tube within that portion of the head.